Freeform fabrication is fast becoming a popular process for manufacturing three-dimensional objects including finished products, prototype parts or models, and working tools. For example, freeform fabrication is used to make products such as structural ceramics and ceramic shell molds. Several methods of freeform fabrication involve a process of sequentially forming layers of the desired end product.
When freeform fabrication involves a process of sequentially forming layers, a number of planar layers are combined together to form a planar or non-planar, three-dimensional object. The object is formed layer-by-layer, with a segment of each layer representing a cross section of the final desired product. Adjacently formed layers are adhered to one another in predetermined patterns to build up the desired product.
In some methods, a layer of the desired product is formed by spreading a layer of powdered build material and then selectively injecting a binder into the powder. Where applied, the binder binds the powder into a cross section of the desired product. In other methods, the build material is selectively ejected to form each sequential layer of the desired product.
There are several disadvantages, however, in conventional freeform fabrication processes, including the fragility of the resulting product. Poor mechanical properties in the final product are a result of a low compression modulus. Poor mechanical properties are also manifested by fragility in extension, or low fracture strength.